SpaceX conducts second ground landing after launch of CRS-9 Dragon to ISS
KENNEDY SPACE CENTER, Fla. — Cargo, experiments, and supplies for the International Space Station’s Expedition 48 crew lifted off the pad at 12:45 a.m. EDT (04:45 GMT) July 18 from Cape Canaveral’s Space Launch Complex 40 in Florida. A SpaceX Falcon 9 launched the CRS-9 Dragon into the dark skies on a two-day journey to the orbiting laboratory.
Less than 10 minutes after rocketing skyward, a triple sonic boom heralded the return of the first stage of the Hawthorn, California-based company’s Falcon 9. The booster lit up the Cape Canaveral skies for the second time that night to touch down at Landing Zone 1 (LZ-1). This was only the second time a rocket booster assisting in sending payload toward orbit, landed back at the landing area.
Reusing the boosters is part of SpaceX’s plan to lower the cost of spaceflight and open up low-Earth orbit for more and more customers. Just over two-and-a-half minutes into the flight, the nine-engine first stage separated from the single-engine second stage.
The second stage continued toward orbit while the first stage pitched over to conduct a “boost back” burn with three of the nine Merlin engines, taking aim for LZ-1. A few minutes later, another burn, the “re-entry burn” was performed to soften the impact on the stage with the atmosphere. This burn also utilized three engines.
In the final moments before touchdown, the center Merlin engine ignited to slow the 150-foot tall stage to zero velocity right at the moment of touchdown. These “hover-slam” maneuvers are necessary for two reasons. First, a single Merlin engine cannot throttle low enough to create a hover. Second, a hover-slam uses less fuel as the engines are fighting back at gravity for less time.
While the landing was a success, the primary mission was lofting Dragon toward the space station. Upon reaching orbit, the two solar panels and Guidance Navigation Control bay deployed. Over the next two days, the spacecraft will fine-tune its orbit and rendezvous with the orbiting outpost.
Early Wednesday morning, Dragon will be close enough to the ISS for the onboard crew to use the robotic Canadarm2 to grab the spacecraft and berth it to the Earth-facing port of Harmony. Hatches will be opened soon after and supplies unloaded.
“Each commercial resupply flight to the space station is a significant event. Everything, from the science to the spare hardware and crew supplies, is vital for sustaining our mission,” said Kirk Shireman, NASA’s International Space Station Program manager via a statement issued by the space agency. “With equipment to enable novel experiments never attempted before in space, and an international docking adapter vital to the future of U.S. commercial crew spacecraft, we’re thrilled this Dragon has successfully taken flight.”
In addition to much-needed commodities such as air, food, and experiments, the cargo ship included a new docking adapter for the ISS—the International Docking Adapter 2 (IDA-2)—located in the trunk of the Dragon spacecraft. IDA-2 will be one of two adapters that will be attached to the existing Pressurized Mating Adapters (PMA) on the orbiting outpost.
IDA-2 will be attached to PMA-2, which is located on the forward end of the Harmony module at the front of the station. This is the second adapter to be launched. The first one, however, was lost during a launch mishap in June 2015. That mission carried the CRS-7 Dragon. During ascent, a strut holding a helium tank inside the second stage broke free, causing the tank to rise and burst the upper dome. As such, the rocket broke apart and the Dragon—with IDA-1—were lost.
A replacement, IDA-3, will be launched sometime in 2018, likely during the CRS-16 mission. Both IDAs will be used to accommodate future commercial crew vehicles—SpaceX’s Crew Dragon and Boeing’s CST-100 Starliner. Both of which are expected to begin uncrewed orbital tests as early as mid to late 2017 with crewed tests to follow soon after.
So far, 2016 has been a banner year for SpaceX. In the eight months since the company’s return to flight after the CRS-7 launch mishap, the firm has launched the Falcon 9 eight times—seven so far in this year. The company plans to launch at as many as 10 more times before the end of December.
In all of its launches so far this year, the company attempted to land the booster’s first stage. In addition to landing on land for the first time in December 2015, the Falcon 9 first stage landed successfully on the Automated Spaceport Drone Ship called “Of Course I Still Love You” 50 percent of the time. The first was during the CRS-8 mission in April 2016. The next two occurred in late and early May.
While the company was making headlines landing rockets on platforms in the ocean, SpaceX also announced that the NewSpace firm would send an uncrewed Crew Dragon to the surface of Mars as early as 2018.
This “Red Dragon” mission would fly atop the yet-to-launch Falcon Heavy. Its debut is expected sometime later this year.
SpaceX’s announcement was part of a larger story. Under a Space Act agreement with NASA, the company will give the space agency data on propulsive landings on the Red Planet in exchange for technical support, such as the use of the Deep Space Network for communications.
A couple of weeks after the announcement, Elon Musk, SpaceX’s founder and CEO, said that the company plans to send at least one mission to the Red Planet during every Mars launch opportunity with the potential to land humans on the surface as early as 2025.
Musk also said that he will announce SpaceX’s Mars plans in September during the International Astronomical Conference in Mexico City. Those plans are rumored to include the Mars Colonial Transporter, a huge rocket speculated to be larger than the Saturn V.
For now, however, the company still has a large backlog of customer payloads to launch. The Japanese JCSAT-16 is the next payload the Falcon 9 will launch. It is expected to occur sometime in August at SLC-40 in Florida. The next Dragon scheduled to fly to the ISS will be in November.
Until then, the CRS-9 Dragon is expected to stay berthed at the ISS for about five weeks before the crew uses Canadarm2 to detach the spacecraft. The craft will then conduct a de-orbit burn to land in the Pacific Ocean not far from the coast of Baja California Peninsula.
“I am proud of the integrated team who worked together flawlessly to make this launch a success,” said Brig. Gen. Wayne Monteith, 45th Space Wing commander, who served as the mission’s Launch Decision Authority. “Everyone’s hard work and dedication paid off today. This mission once again clearly demonstrates the successful collaboration we have with our mission partners at NASA and SpaceX as we continue to shape the future of America’s space operations, and serve as the World’s Premier Gateway to Space.”
Video courtesy of SpaceFlight Insider
Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology, Space.com, The Mars Society and Universe Today.